# Relationship history for MSHA mine 2102607

Current hierarchy: **Kent O  Roberson → Roberson Lime & Rock, Inc. → Roberson**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Roberson Lime & Rock, Inc. → Roberson; 1978-03-09 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Kent O  Roberson et al → Roberson; 1978-03-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kent O  Roberson et al → Roberson Lime & Rock, Inc.; 1978-03-09 to current/open; source msha-controller-operator-history